This invention relates to devices for positioning medical instruments.
Surgical procedures, e.g., those involving minimally invasive endoscopic surgery, require simultaneous use of numerous instruments by a physician. Often the procedure is complicated and one or more assistants may be required to hold one or more of these instruments in position. These assistants tend to congest the area around the operating table and restrict movement by the physician performing the surgery.
To address this problem, arms to hold surgical equipments have been suggested. For example, Bonnell (1989, U.S. Pat. No. 4,863,133, by one of the inventors here) discusses an articulated instrument support arm that employs vacuum switch controls to set the position of the arm with lightly loaded restraint. Milo (1975, U.S. Pat. No. 3,858,578) describes a flexible arm for holding surgical instruments, the joints of which can be simultaneously locked in place, using hydraulic pressure to tension a cable extending axially through the assembled arm elements. Poletti (1972, U.S. Pat. No. 3,638,973) and Kimoshita (1976, U.S. Pat. No. 3,986,692) describe jointed arms which can be fixed in position by hydraulic pressure.